Yes, as Hyejeong says, it is most probably a question asked by a Korean of a foreigner residing in a different country. Other scenarios don't seem to make much sense. And I would guess it is said like 한국(에) 온 적(이) 있어요? (Have you ever been to Korea?). One could also say 한국(에) 와 본 적(이) 있어요? or 한국에 와 봤어요?

Hum wait no, I THINK you can't use 오다 because from your perspective you GO (가다) to Korea. So I think it's a question asked by a Korean person, from their perspective you COME (오다) to Korea. So it could actually mean "Have you ever been to Korea?" Can any native speaker help here? I'm not quite sure about this one.

I'll do it for you Gertie. :p 한국 = Korea -은/는 = topic particle 온 = comes from 오다 (to come) -ㄴ 적 있다 = a grammatical structure used to talk about experiences So as Gertie said it means "I have been to Korea." but I don't think it could translate to "I have come to Korea" since with "have come" you're saying that you're still there. And if you were still there, you obviously wouldn't say such a sentence. ^^

I have been(come) to Korea. I would break it down more, but I don't have a Korean keyboard right now.